In 1962 and 1964, two rootstocks of apple (Malus pumila Mill.), ‘Malling-Merton 106’ (nonpatented) (Seed parent) and ‘Malling 27’ (nonpatented) (pollen parent), both not patented, were crossed in a cultivated area of West Malling, Kent, England. These crosses produced 56 (AR10 series) and 59 (AR86 series) seedlings, respectively. After the completion of preliminary screening tests, eight seedlings from the AR10 series and seven from the AR86 series were selected and propagated in 1973 for further evaluation. The vigour of each selection, when grown as hard-pruned hedges in the nursery, was recorded between 1979 and 1983. The potential vigour of the selections when used as rootstocks was estimated from measurements of the percentage of bark tissue in young roots, using techniques first described by Beakbane and Thompson (1947) and later modified by Werts et al. (1976). This percentage root bark was measured a number of times between 1974 and 1980 on root samples from all of the 15 selections. One of the seedlings, ‘AR 86-1-25’ (nonpatented) had 52% rootbark.
The ability of these selections to root and establish from hardwood cuttings was assessed in a minimum of six separate propagation trials conducted during 10 years. In each test the rooting and subsequent establishment of hardwood cuttings of each selection were evaluated using techniques developed at East Malling Research Station (Howard, 1971). For ‘AR86-1-25’ (nonpatented), 63% of cuttings rooted and established in the field.
The incidence of mildew (Podosphaera leucotricha) was observed over several years on most of the selections growing as hedges and receiving the standard East Malling Research Station nursery spray programme for pests and diseases. ‘AR86-1-25’ (nonpatented) was found to be relatively resistant. The selections were scored for resistance to woolly apple aphid (Eriosoma lanigerum) in tests on small potted specimens grown under glass (Lyth and Watkins, 1981). The rating of ‘AR86-1-25’ (nonpatented) was inconclusive but it has since been recorded as resistant. The selections were also scored for resistance to collar-rot (Phytophthora cactorum). ‘AR86-1-25’ (nonpatented) was rated as fairly resistant. Finally, the field resistance of many of the selections to specific apple replant disease (SARD) was evaluated (Oehl and Jackson, 1980). ‘AR86-1-25’ (nonpatented) was considered resistant.
‘AR86-1-25’ (nonpatented) was first asexually reproduced in 1973 in East Malling, Kent, England by hardwood cuttings and subsequent generations have been true to phenotype.